Impact of atmospheric pollution on the protein and amino acid metabolism of spruce Picea abies trees

Abstract

Ten 80-year-old spruce Picea abies trees from a forest district on the south side of the Taunus mountain range adjacent to the densely populated Rhine-Main area were analysed for their protein and amino acid metabolism.

The quantities of SDS-soluble proteins in the youngest needles decreased slightly with increasing defoliation of the trees, but SDS-protein patterns remained constant. In the youngest needles, however, proteinogenous amino acids increased severalfold with increasing needle loss. Arginine, threonine, isoleucine, alanine, tyrosine, lysine, histidine, leucine, methionine,and serine increased about 300%, valine and glycine about 250%. On the other hand, the contents in phenylalanine decreased about 60% and, in cysteic acid, about 22%. Chlorophyll contents in the youngest needles were relatively constant (no yellow needles present). The amount of dry matter increased slightly.

The rise in amino acid concentrations which wer observed is severalfold higher than that estimated 10 years ago in areas polluted by gaseous SO₂. We suggest that the increasing contents of amino acids are attributable to high amounts of ammonia which have accumulated in the forest soil.